Maximum fuel mileage will be obtained with widest throttle opening and lower RPM, provided that the ECU remains in closed loop mode to keep the mixture stoiciometric. Specifically, when boost begins, the ECU is taken out of closed loop mixture control, and the mixture richens. The more an engine is throttled, the lower the efficiency. So, a 3.73 rear with a taller fifth gear should result in better fuel economy, but downshift going up grades if boost begins.
New 5th gear for the R154 - how about a taller overdrive?
- Thread starter Doward
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Cz.;1304073 said:
FTFY.............at least you won't have to worry about being a vegetable, cause there's no way you're going to live through it. Maybe at 160 you have a one percent chance of living, but not at 210.........:evil2:
Now, I have to go back and read the last few pages to see what I've missed.
All kinds of stuff, Jay. When gas prices go back up, I'd like to know I'm knocking 30+ in my Supra, so I can justify driving it on long trips 
Guyana00;1297244 said:
Probably from Chevy trans. Guys in Jersey have been doing it for years I've been told.
Yep, it would definitely increase the top speed
Top speed in my setup - 3.91 rear / 26" tall tire - (provided I can redline 7400rpm in 5th) would be ~ 222 mph.
Top speed in my setup - 3.91 rear / 26" tall tire - (provided I can redline 7400rpm in 5th) would be ~ 222 mph.
Clueless;1299875 said:
As test subject I will see how it handles 2 step launches and no-lift shifting.
I'm finishing the transmission rebuild, then we'll be putting this into Jeff's car for a full test
So you would be up for rebuilding the transmission as well? I assume you would be ok with installing the martin crawler parts if we supply them?
I'd practically require the MC parts.
The stock bearing retainer is total shit, and the 1st gear thrust washer is a known weak point.
I'll be doing no more than 3 or 4 such rebuilds, though. If you're dead set on it, I suggest you get in line quickly.
The stock bearing retainer is total shit, and the 1st gear thrust washer is a known weak point.
I'll be doing no more than 3 or 4 such rebuilds, though. If you're dead set on it, I suggest you get in line quickly.
Standby for pics!
New 5th gear on the right, old 5th gear on the left (to give you an idea of size difference):
New Nylon spacer for the 1st gear bearing:
1st gear in with the new synchro:
MC 1st gear solid thrust washer:
MC HD Bearing Retainer Plate + 5th gear Counter gear:
Speedometer driver gear installed / 5th gear counter assembly installed / Shift fork installed:
Here you can see a little something I like doing to the shift rods - I did a light polish on the top one, and the other two are not done yet. Nothing like helping it slide easier:
All the shift rods / forks installed:
Various views:
Reverse idler gear:
Magnet:
Assembly:
Front case:
Front assembled:
So what are we waiting on? The tail housing is cleaned and ready to go - I'm waiting on a snap ring from Toyota (K-mark for the output shaft bearing) and then the tail goes on, and off to Jeff's for testing!
New 5th gear on the right, old 5th gear on the left (to give you an idea of size difference):
New Nylon spacer for the 1st gear bearing:
1st gear in with the new synchro:
MC 1st gear solid thrust washer:
MC HD Bearing Retainer Plate + 5th gear Counter gear:
Speedometer driver gear installed / 5th gear counter assembly installed / Shift fork installed:
Here you can see a little something I like doing to the shift rods - I did a light polish on the top one, and the other two are not done yet. Nothing like helping it slide easier:
All the shift rods / forks installed:
Various views:
Reverse idler gear:
Magnet:
Assembly:
Front case:
Front assembled:
So what are we waiting on? The tail housing is cleaned and ready to go - I'm waiting on a snap ring from Toyota (K-mark for the output shaft bearing) and then the tail goes on, and off to Jeff's for testing!
Doward;
I know either way i would be vary interested in getting one, due to the fact that i have to drive almost 100miles just to get anywhere, and its all basicly flat, plus i drive at 80, not 70.
What kinda price tag would i be looking at would you say right now for a complete "shorter" 5th gear and all?
I know either way i would be vary interested in getting one, due to the fact that i have to drive almost 100miles just to get anywhere, and its all basicly flat, plus i drive at 80, not 70.
What kinda price tag would i be looking at would you say right now for a complete "shorter" 5th gear and all?
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